The overall life-cycle of engineered systems typically starts with a requirements capture for a system model being designed and continues to the maintenance of the deployed real-life system based on the model. Frequently, the maintenance of the deployed system costs as much as the initial design of the system with the result that good maintenance technologies have taken on an increased importance.
Much of the present day repair aspect of maintenance schemes relies on the use of measurement trees. Measurement trees are a hierarchical tree-like arrangement of acceptable operating parameters for different components in a system. Starting from a root diagnosis as to which component may be faulty in a system, a selection of measurements can be made on the system that is behaving erratically. Each of the measurements rules out a number of branches on the tree which relate to different sub-components of the suspected faulty component. As a path along the tree is traversed by making additional measurements, a detected failure can ultimately be pinpointed to a replaceable component.
Conventionally problems with deployed systems based on a computer designed model have been diagnosed using two types of mechanisms. Diagnosis of problems has been made through the use of heuristics or the previous experiences of the user tasked with identifying the cause of the system fault. Some analysis is performed through a combination of the mechanisms. Unfortunately these approaches fail to take advantage of the information gathered during the design phase of the system when the system model undergoes testing to make sure it satisfies the set of requirements for the system design.